昆虫多巴胺及其受体的研究进展及展望

多巴胺(dopamine,DA)是一种重要的神经递质,通过特异地结合其相关的多巴胺受体(dopamine receptors,DARs)发挥作用。昆虫DARs可分为D1-like DARs,D2-like DARs和多巴胺/蜕皮激素受体(dopamine/ecdysteroid receptor,DopEcR)。D1-like DARs包含两种亚型即DOP1和DOP2,都能偶联G s蛋白引起胞内cAMP上升,且DOP2还能偶联G q蛋白引起胞内Ca 2+浓度升高;D2-like DARs只有一种亚型DOP3,偶联G i蛋白导致胞内cAMP下降;DopEcR可以同时被DA和蜕皮激素激活。本文综述了近年来关于昆虫DA的调控、多巴胺神经元、DARs的药理学特性及生理功能等方面的研究进展。DA合成、转运和降解过程中的基因调控昆虫的多种表型,如表皮黑化、翅的颜色和图案等。DA在多巴胺神经元中合成和释放,不同类型的多巴胺神经元参与调控不同的功能。随着近年来单细胞测序和DA实时成像技术的兴起,这将有利于进一步探讨特异神经元的功能。不同昆虫DARs的激动剂和拮抗剂活性存在很大异同,这些药理学差异将为以昆虫DARs为作用靶标开发高效选择性杀虫剂提供重要依据。DARs参与调控昆虫的多种生理与行为过程,如取食、学习、记忆、遗忘、求偶、交配、睡眠及觉醒等。随着CRISPR/Cas9技术在不同昆虫中成功地应用,以及结合模式昆虫黑腹果蝇中丰富的遗传学操作手段,这些都将有利于精准解析DARs的功能。

Research progress and prospects of dopamine and its receptors in insects

Dopamine(DA)is an important neurotransmitter,and exerts its effects via specifically binding to dopamine receptors(DARs).Insect DARs can be divided into D1-like DARs,D2-like DARs,and dopamine/ecdysteroid receptor(DopEcR).D1-like DARs have two subtypes,DOP1 and DOP2,both increasing intracellular cAMP via coupling to G s signaling,and DOP2 can also activate G q to mobilize intracellular Ca 2+signaling.D2-like DARs have only one subtype,DOP3,decreasing intracellular cAMP via coupling to G i signaling.DopEcR can respond to both DA and ecdysteroids.In this review,we summarized the research progress of the regulation of DA,dopaminergic neurons,and pharmacological properties and physiological functions of DARs in insects in recent years.The genes in the processes of biosynthesis,transport and degradation of DA regulate multiple phenotypes,such as cuticle melanization,wing color and morphology of wing scales.DA is synthesized and released in dopaminergic neurons,and different types of dopaminergic neurons have different functions.With the development of single-cell sequencing and DA real-time imaging technologies in recent years,this will be beneficial to further investigate the functions of specific neurons.The activities of agonists and antagonists of DARs among insects are very different.These pharmacological differences will provide important basis for developing highly effective and selective insecticides targeting insect DARs.DARs are involved in regulating various physiological and behavioral processes in insects,such as feeding,learning,memory,forgetting,courtship,mating,sleep and wakefulness.The continuously successful application of CRISPR/Cas9 in various insects,as well as the combination of abundant genetic manipulation techniques in Drosophila melanogaster,will facilitate us to accurately investigate the functions of DARs.